Luke Shumaker authored Mar 15, 2018 and Eli Schwartz committed Apr 08, 2018

Search for unquoted variables using the command:

    grep -Prn --exclude-dir=.git '(?<!["=]|\[\[ |\[\[ -[zn] )\$(?!{?#|\(|\? )'

and ignore a bunch of false positives.

You may verify that the only differences between the lines removed and
lines added are double-quotes:

        diff -u \
          <(git show|sed -n 's/^-//p'|grep -v '^-- a/'|sed 's/"//g') \
          <(git show|sed -n 's/^+//p'|grep -v '^++ b/'|sed 's/"//g')